Double walled box



Jan. 27, 1959 G. E. STRUBLE DOUBLE WALLED BOX Filed Aug. 23, 1955 FIG-1 2 Sheets-Sheet 1 INVENTOR.

GLENN E. STRUBLE ATTORNEYS G. E. STRUBLE DOUBLE WALLED BOX Jan. 27, 1959 2 Sheets-Sheet 2 Filed Aug. 23. 1955 INVENTORI GLENN E. STRUBLE ATTORNEYS nited States atent Dfiice 2,870,951 Patented Jan. 27, 1959 2,870,951 DOUBLE WALLED Box Glenn E. Struble, Hamilton, Ohio, assignor, by mesne assignments, to Diamond Gardner Corporation, a corporation of Delaware Application August 23, 1955, Serial No. 530,011

Claims. (Cl. 229-34) This invention relates to a double walled box, particularly to a construction for forming corners on such a box and for locking the box in erected position.

One of the principal objects of this invention is to provide a double walled box of improved design having corner constructions which securely lock the side walls and end walls of the box into erected position.

Another object of the invention is to provide such a box wherein double Walled locking sections extend as integral portions of the box side Walls and are foldable at right angles to the side walls for extension across the ends of the box to be enfolded within the end walls, and wherein the integral connection between the locking sec tions and the side walls includes folding panels which move into face to face relation within the corner of the erected box.

A further object of this invention is to provide such a double walled box from a unitary blank of sheet material which is appropriately scored and slit with a minimum of waste material, and which is foldable along the score lines into a box having improved and substantially strengthened construction particularly at its corners.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings- Fig. 1 is a plan view of the unitary blank of sheet material from which the box of this invention is formed;

Figs. 2, 3, 4, 5, 6 and 7 illustrate sequential steps in the assembly and erection of one corner of the box from the blank of Fig. 1;

Fig. 8 is a top view, partly=in section and elevation, of one corner of the erected box;

Fig. 9 is a perspective view of one corner of the erected box; and

Fig. 10 is a perspective view of the completed box with one end wall fully completed, and the other end wall readied for folding into erected condition.

partly in Referring to the drawing, which illustrates a preferred embodiment of the invention, and particularly to Fig. l, the unitary blank of sheet material from which the box of this invention is formed is illustrated with dotted lines indicating score lines in the blank separating it into a main or bottom panel 10 having integral extensions from its opposite sides foldable alongscore lines 11 into an upright position with respect tobottom 10. Each of these extensions is also provided with longitudinal score lines extending parallel to the main fold line 11 and dividing the extensions into side walls including outer panels 12, top panels 13, inner panels 14 and bottom panels 15. These side wall panels arefoldable over and over to pro vide a hollow side wall of substantially rectangular cross section, asseen in Fig. 5.

The bottom side Wall panels 15 are secured (preferably by adhesive) to bottom 10 to maintain the proper spacing of the inner and outer side Wall panels 12 and 14, but when the blank is madeup into flattened form for shipping or storage (as in Fig.3) this connection does a 2 not interfere with the flattening of the side walls to provide a flat knocked down box. From the other edges of bottom 10 extend integral members hinged thereto along score lines 16, and each of these extensions is divided by score lines parallel to lines 16 to provide end walls including outer panels 17, top panels 18, inner panels 19 and bottom or tuck panels 20. When the box is erected these end wall panels are folded over and over inwardly toward the bottom 10 to provide end walls which are also of substantially rectangular cross-section.

To lock the hollow side and end walls in the erected condition, each corner of the box is provided with a locking section indicated generally at and including outer panel 26, top panel 27, an inner panel 28, a short bottom panel 29 and a glue flap 30 integral with outer locking section panel 26. At the same time the side walls are formed by attachment of their bottom panel 15 to the bottom 10, the short locking section bottom panels 29 are attached to glue flaps 30 to provide, in knocked down form, the hollow locking sections which are erectable along with the hollow side walls into members of substantially rectangular cross-section. The locking sections are separated from the end wall panels by a slit 32 separating outer end wall panel 17 from panel 26, and by a curved extension 33 of slit 32 separating the top end wall panels 18 from glue flaps 30. A continuation of the slit at 34 separates inner end wall panels 19 from glue flaps 30, and the rounded out at the corner of tucking panels 20 separates them from glue flaps 30. Thus, each locking section 25 is entirely separate from the end Walls of the box.

An integral hinge connection is provided between each of the locking sections 25 and the side walls. This connection includes a score line 35 separating panels 12 and 26, and score lines 36 separating the connection between panels 14 and 28 into two gusset panels 40 and 41 hinged to each other and to the inner side wall and locking section panels 14 and 28, respectively. That portion of the blank extending between bottom side Wall panels 15 and bottom locking section panels 29 along the gusset panels 40-41 is removed to provide clearance for the corner folding operations to be described presently.

The top side wall panels 13 and the top locking section panels 27 are separated from each other by the vertical leg 45 of a T-shaped slit, and the horizontal leg 46 of this slit separates the panels 40 and 41 from the top panels 13 and 27 respectively. This slit provides for sliding movement of top panels 13 and 27, one upon the other, during folding of the erected locking sections 25 across the ends of the box at right angles to the side walls. During this folding action the panels 40 and 41 how inwardly into the hollow side walls at the corners of the box, into face to face relation with each other, and the end wall panels 17--20 are then folded about the locking sections 25. When the bottom end wall or tucking panel is pushed between the bottoms of the locking sections and the bottom 10, the end walls are locked in place, and consequently the entire box is locked into its erected position.

Referring to Fig. 2, one corner of the blank is shown in an intermediate step of assembly into flat-folded form. The bottom side wall and locking section panels 15 and 29, respectively, have a suitable adhesive applied to them, as by the glue Wheel shown at 48 in Fig. 1. These portions of the panels are to be. folded into abutting relation with the shaded portions on bottom 10 and glue flap 30.

After application of the adhesive, the side and end Wall panels are folded over along the score line separating panels 13, 14 and 27, 28 as in Fig. 2, and the side and end wall panels are then folded over along line 11, as in Fig. 3. In this form the. blank is in a knocked-down condition wherein it is flattened for shipping or storage.

Fig. 4 illustrates the erection of the side walls and locking sections, wherein the inner and outer side wall and locking section panels are folded upwardly at right angles with respect to the bottom'lt). Fig. 5 illustrates in perspective the corner of the box in the same conditionas shownin plan in Fig. '4.

The locking section is then folded inwardly, as indicated by arrow 50 in Fig. 6, until the locking section extends at right angles with respect tothe side wall, and the entire locking section overlies bottom 10 Within the score lines 16. During this folding operation the gusset panels and 41 bow inwardly into the corner of the box, as shown inFig. 6, and at the same time the inner corners of top sidewall panel 13 and top locking section panel 27, being freed from each other by the T-shaped slit 46, slide one under the other, preferably with the corner of panel 27 passing underneath the corner of panel l3. When the locking section has completely folded across the end of the box the panels 40 and 41 are face to face within the corner'of the box, as seen in Fig. 8.

The end wall panels are then folded upwardly about score lines 16, and about the score lines separating them into individual panels, and the bottom or tucking end wall panel 30 is slipped beneaththe bottom of the locking section 25 to hold the box in erected condition. The final relation of the end wall panels is shown in Fig. 9, with the rounded corner of the top panel 18 as provided by slit 33, resting in super-posed position upon the other panels at the corner of the box.

It will thus be seen that the present invention provides a double walled box construction wherein the corners of the box, in addition to providing a sealed double walled box construction, also lock the box into its erected position and provide a corner of substantial strength which is highly resistant to crushing and the like. This is emphasized by noting that at the top of each corner there are three thicknesses of sheet material provided by the overlapped corner of panels 13, 27 and 18, and that these overlapped portions are vertically supported by a double thickness of sheet material in the form of the vertically extending gusset panels 40 and 4i within the corners of the box. 7

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. A blank for forming a double walled box of the character described, comprising a unitary sheet of material scored to provide a bottom, side walls each including outer, top, inner and bottom panels extending in that order from one edge of said bottom and foldable into tubular form with'said bottom side wall panel adapted for securing to said bottom, end walls, each including outer, top, inner and bottom panels connected in that order and foldable into tubular form with said bottom panel overlying said bottom, corner locking sections at opposite ends of said side walls and each including inner,

' outer, top and bottom panels foldable into tubular configuration, a glue flap on each said outer locking section panel for attachment to said bottom locking section panel, said locking sections being free of direct connection with said end walls and having integral hinged connections with said side wall through said inner side wall panel and said inner locking section panel and through said outer side wall and said outer locking section panel, the connection between said inner side wall panel and said inner locking section panel including a pair of gusset panels adapted for folding into abutting relation within said hollow side wall at the corner of the erected box, and said top side wall and'top locking section panels being separated from each other and from the adjacent edge of said gusset panels by a T-shaped slit through said blank providing for overlapping of said top side wall and top locking section panels and for inward folding of said gusset flaps after said locking section is folded into position extending across the end of the box.

2. A double walled box of the character described, comprising a bottom, four panel hollow side walls provided with outer, inner, top and bottom panels joined into tubular configuration, locking sections at opposite ends of said side walls and each including outer, inner, top and bottom panels and a glue flap joining said locking section panels into tubular configuration, said outer looking section panels and said outer side wall panels being hingedly connected along a common fold line for folding of said locking sections across the ends of said box, said top locking section panels and said top side wall panels being separated by a slit providing for overlapping thereof during folding of said locking sections across the ends of the box, and end walls including inner, outer, itop and bottom panels foldable independently ofsaid locking sections to enclose said locking sections with said bottom end wall panels locking beneath said locking sections.

3. A double walled box of the character described, comprising a unitary sheet of material providing a bottom, a hollow side wall having an integral connection with said bottom and including outer and inner panels separated by a top panel, a bottom panel on said side wall secured to said bottom retaining said sidewall panels in open tubular configuration, a corner locking section including an outer panel having an integral hinged connection with said outer side wall panel and an inner panel having a folding hinged connection with said inner side wall panel, a top locking section panel joining said inner andouter locking section panels and separated from said top side I wall panel by a first slit through said sheet material, said folding hinged connection including a pair of gusset panels separated from said top side wall and locking section panels by another slit extending across the end of said first slit bordering on said inner panels, said locking section being foldable substantially at right angles with respect to said side wall about said hinge connection between said outer side wall and locking section panels, said gusset panels being arranged for movementinto face to face relation within the corner of the erected box, the

slitted ends of said top side wall and locking section panels being slidable one upon the otheryat the corner of the erected box, and an end wall including inner, outer, top and bottom panels for enfolding said locking section with said bottom end Wall panel tucked beneath said locking section to lock the box in erected condition.

4. A double walled box of the character described comprising a bottom, integral extensions from two opposite sides of said bottom providing hollow side walls each including outer, top, and inner panels, botto'm flaps on said side walls secured to said bottom, integral extensions from the other sides of said bottom providing end walls including outer, top, inner and bottom panels, said inner and bottom end wall panels having cut away portions at their opposite ends, said cutaway portions being equivalent in width to the thickness of said side walls, integral extensions from said outer and inner side wall panels providing corner locking sections including inner, outer, and top locking section panels, saidtop locking section panels being separated from said top sidewallpanels. by the vertical leg of a T-shaped slit, and the horizontal legof said slit separating adjoining portions of said inner side wall and inner locking section panels from their respective adjoining top panels to define an integral hinged connection between said inner side walls and said inner locking section panels said hinged connection including a pair of gusset panels foldable inwardlywithinsaid side walls in face to face relation with each other as said locking sections are folded across the ends of said box into position to be enfolded by said panels of said end walls.

5. A blank for forming a double walled box of the character described, comprising a. unitary sheet of ma- 5 terial scored to provide fold lines defining a rectangular bottom, four panel side walls extending from opposite sides of said bottom and each including outer, top, inner and bottom panels extending in that order from the side edges of said bottom and foldable into tubular form, said bottom side wall panels being securable to said bottom for retaining said side walls in tubular form, end walls extending from the other edges of said bottom, each end Wall including outer, top, inner and bottom panels connected in that order and foldable into tubular form with said bottom panel overlying said bottom, said end Wall inner and bottom panels being of a length less than said end wall outer and top panels by a distance at each end substantially equal to the width of said side wall top panels, comer locking sections atopposite ends of said side walls and each including inner, outer, top and bottom panels foldable into tubular configuration, said outer look ing section panel being separated from said end wall outer and top panels by a slit, glue flaps extending from each of said outer locking section panels to adjacent said end wall inner and bottom panels and being separated from the latter by a slit in said blank providing for folding of said corner locking sections independently of said end walls, said bottom panels of said locking sections being rating said outer side wall panels and said outer locking section panels, and said top side wall and top locking section panels being separated from each other and from adjacent edges of said gusset panels by a slit providing for overlapping of said top side wall and top locking section panels during folding of said locking sections across the ends of said box.

References Cited in the file of this patent UNITED STATES PATENTS 2,588,377 Frankenstein Mar. 11, 1952 2,603,403 Thompson July 15, 1952 2,612,306 Frankenstein Sept. 30, 1952 FOREIGN PATENTS 287,740 Switzerland Apr. 16, 1953 

